This invention relates to a collapsible steering assembly for an automotive vehicle, and more particularly to a steering assembly that is adapted to slide forwardly in a crash situation, thereby lessening injuries that might be experienced by the driver of the vehicle.
Collapsible steering assemblies are shown in U.S. Pat. No. 4,616,522 issued to George White et al, and U.S. Pat. No. 5,024,118 issued to Mustafa Khalifa et al. In a typical steering wheel assembly the steering column has two laterally-extending ears that have releasable connections with a mounting bracket for the steering column. These connections normally retain the steering column in a fixed condition relative to the mounting bracket. In a crash situation the body of the person in the driver seat may forcibly impact the steering wheel, thereby applying a forward force to the steering column. The connections between the aforementioned ears and the mounting bracket are released, or severed, thereby enabling the steering column to slide forward relative to the mounting bracket so as to relieve the impact force on the person in the driver seat.
The present invention relates to a collapsible steering assembly that is relatively compact and adapted for low manufacturing cost. The collapse action is achieved by means of a direct frictional connection between the steering column and a plastic block carried by the associated mounting bracket. In preferred practice of the invention the frictional connection is provided by raised surfaces on the steering column, and mating depressions formed in the plastic block. During normal operation of the vehicle the depressions frictionally grip the raised surfaces so that the steering column remains motionless relative to the mounting bracket. During a crash situation, a forward axial force on the steering column causes the raised surfaces to slide forwardly along the depressions, thereby relieving the impact force on the person in the driver seat.
The aforementioned plastic block can be designed to include a transverse mounting hole for a steering wheel lock. In one particular embodiment of the invention, a tiltable steering wheel is connected to the upper end of the steering column. The steering wheel can be tilted to various positions, and locked in place by a manually-operated lock mechanism that is mounted to the aforementioned plastic block. The plastic block thereby serves a dual purpose, first as a frictional retention means for the steering column, and second as a mounting means for the steering wheel lock mechanism.
A principal advantage of the invention is that the crash-responsive mechanism for controlling collapse of the steering column is relatively compact and adapted for relatively low manufacturing cost. Specific features of the invention will be apparent from the attached drawings and description of an illustrative embodiment of the invention.